I wouldn't use the term "feminist extremists" because I don't think that this actually has all that much to do with feminism. This is about having employed black and white thinking in relation to an issue which is all shades of grey.
People whose beliefs are at one end of this particular spectrum believe that the rights of the foetus trump all other considerations, including the rights and in some cases the life of the woman. They would advocate for a total ban on abortion.
We have seen the reality of what they are calling for in countries where there is, or has been, a total ban on abortion. We've seen the tragic outcomes including women dying due to pregnancy complications, women being forced to carry babies with no chance of survival to term, women dying from botched backstreet abortions, women travelling to another country to access safe healthcare, and women being forced to give birth to unwanted children. Clearly, these are not things which should be happening in any country which values women's lives.
People whose beliefs are at the other end of the spectrum believe that the woman's bodily autonomy is paramount and that this trumps all other considerations, full stop. They would advocate for women to be able to access an abortion at any point in her pregnancy, for any reason, i.e. for there to be no hard limits.
We have not seen the reality of what they are calling for because almost all, if not all countries which allow abortion have imposed legal limitations on the reasons why a woman can request an abortion and the gestation before which she must do so. In practice, in every country in the world which allows abortion, there comes a point in time at which a woman carrying a healthy foetus can no longer choose to end her pregnancy and must see it through to the end. Anyone who says we don't need legal limits on abortion because no woman would actually choose to terminate her healthy pregnancy on her due date is speculating.
What I find really telling is that a lot of people who have adopted the "any time, for any reason" position will refuse to answer the question about whether a woman should be allowed to have an injection to stop her healthy baby's heart when she is actually in labour, and if so, whether doctors should be forced to do this if she requests it.
I am virtually certain that almost none of the people in this camp actually think a woman should be allowed to do this, and if it actually happened they would be horrified, despite the fact that they are the ones claiming to believe it should be legal. That means that they do actually think there should be some limits, they just don't want the responsibility for deciding what those limits should be. They want to achieve the true feminist victory of removing all and any obstacles to a woman seeking an abortion, and then sit back and "trust women" and "trust doctors" to ensure that atrocities and safeguarding failures do not occur.
Because they will never be in this position. They're not obstetricians or midwives tasked with delivering full term babies whose deaths they have procured. They know how to access contraception so they're far less likely to have an unwanted pregnancy in the first place (compared to the women whose interests they claim to be fighting), and if they did, they would know how to get an abortion well before 24 weeks. They will never be a mentally unwell woman who is 22 weeks pregnant and really not coping, who is led to believe that she has another 18 weeks to decide and then finds herself going into premature labour at 32 weeks, or desperately trying to find a doctor who will perform an abortion at 36 weeks. They will never be an abused woman whose ex partner wants to force her to have an abortion and who just wants to get to 24 weeks so that he can't do anything to get her to end her pregnancy. They'll never be anywhere close to the vulnerable women they are talking about or their care providers, so if the decision is left in the hands of those people and they get it wrong, they'll never know or care.
If you are seriously advocating for there to be no hard legal limits to abortion, what you are saying is that you hope there will never be any extreme cases (ignoring the fact that any abortion which wouldn't be permitted in the UK under the current law is already an extreme case) but that if there is an extreme situation, you want to rely on the people involved to make the right decision. You're hoping there will be a grown up in the room who will know what to do. And that grown up will not be you, thank goodness.
I think that's a cop out, personally. And I do not think the kind of legal uncertainty you want to introduce is likely to benefit anyone.